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Page 13
KN INSTALLATION AND OPERATION INSTRUCTIONS
Water piping
(continued)
Figure 8
Suggested piping — single boiler — zone valve zoning — two-pipe or series loop (left), or primary/secondary piping (right)
L
egend
• • • • • • •
1
K N
boiler
2
Boiler circulator
3
System circulator
4
Boiler/system circulator
5
Indirect-fired DHW tank
(when used)
6
DHW circulator
7
Flow/check valve
8
Cold water fill line
9
Expansion tank (shown with diaphragm-type — see
page 12 for piping a closed-type tank)
Expansion tank (shown with diaphragm-type — see
page 12 for piping a closed-type tank)
10
Air separator with automatic air vent (Replace air vent
with piping to the tank fitting on closed-type expansion
systems.)
11
Low water cut-off (when required)
12
Extra high limit (when required)
13
Zone valve
14
Zone circulator
15
Differential pressure by-pass valve — Use when high-
head circulator may cause noise, erosion or valve lifting
problems when only a few zone valves are open.
16
Boiler postpurge circulator (see page 11)
K N-2
only
17
Header sensor, required where shown
Isolation valve
Purge valve — Suggested locations allow for improved
system filling and draining and initial air elimination.
Temperature gauge
Zoning with zone valves
Flow balancing and control
On large systems, or when using a high-head circulator, install a differential
pressure by-pass valve to limit the head applied to the zone valves.
Some systems may require balancing valves to control flow in the loops.
DHW operation, when required
The piping shown throughout this manual allows for domestic water
heating without flow through the heating loop(s). This is important for
summertime operation of DHW tanks.
Make sure to incorporate flow/check valves as shown. These prevent forced
flow in idle zones.
5
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